1. Field of the Invention
The present invention relates to improvements in filter means for removing dust from a gaseous fluid, notably air.
2. Description of the Prior Art
Filter means or precipitators for removing dust from gaseous fluids, notably air, are already known and comprise as a rule filter elements having specific physical properties, associated with a load apparatus. The gaseous fluid containing solid particles or dust to be eliminated, which is to be fed to this apparatus, is forced through the filter element in which the finer particles in particular are retained. Generally, the coarser particles cannot pass through this filter element and are stopped by its outer surfaces, so that in most instances they clog the filter element well before its actual capacity of retaining the other, finer particles are fully exploited. On the other hand, it is known that with filter means of the type broadly mentioned hereinabove a kind of compromise is aimed at since two essential parameters are kept into account, namely on the one hand the surface area of the filter element which is subordinate to the total amount of solid particles likely to be "stored" potentially by this filter element, and on the other hand the velocity of penetration at which these particles pass through the filter element, this speed being subordinate to the capacity of these particles to penetrate into the filter material and consequently to the actual degree of utilization of the filter element, through its whole thickness. Now, in known filters of the above-mentioned type and for a given filtrated gaseous fluid throughout, this necessary compromise is generally scarcely obtained, either because it favors the filter surface area, with the twofold inconvenience of excessive over-all dimensions and a reduction in the penetration speed, resulting in a poor exploitation of the filter through its whole thickness, or because it favors the penetration speed, and in this case the total amount of solid particles that can be stored in the filter element remains relatively low. Thus, in any case, the filter is not utilized to its maximum capacity and/or its useful life is abnormally short, with all the inconveniences resulting from these unfavorable conditions.